Resuscitation Outcomes Consortium Epistry Research Articles

Development of a clinical decision rule for the early prediction of Shock-Refractory Out-of-Hospital cardiac arrest

BackgroundNearly half of ventricular fibrillation or ventricular tachycardia (VF/VT) out-of-hospital cardiac arrest (OHCA) patients receive three or more shocks, often referred to as refractory VF/VT. Our objective was to derive a clinical decision rule (CDR) for the early stratification of patients into risk categories for refractory VF/VT. MethodsWe included adults with non-traumatic OHCA in the Resuscitation Outcomes Consortium Epistry (2011–2015) with ≥ 1 EMS shock. We used Classification and Regression Tree analysis for CDR building using variables known at initial EMS rhythm analysis including age, sex, witness, location, bystander interventions, initial EMS rhythm, obvious non-cardiac etiology, and dispatch to arrival times. The outcome was refractory VF/VT (≥3 shocks). We calculated sensitivity, specificity, area under the receiver operating curve (AUROC), and odds ratios (OR). The rule was validated using the Portland Cardiac Arrest Epidemiologic Registry (2018–2020). ResultsThere were 17,140 eligible patients and 8,146 (47.5%) had refractory VF/VT. The optimal CDR (AUROC = 0.671) defined three groups: high-risk were any patients requiring an EMS shock after a bystander AED shock; moderate-risk were any non-EMS witnessed arrests with shockable initial EMS rhythms; and the remainder were low-risk. Refractory VF/VT increased across the low (30.7%), moderate (58.5%) and high-risk (84.8%) groups. Compared to low-risk, being moderate-risk or higher (OR [95% CI]:3.37 [3.16–3.59]; sensitivity 72.7%; specificity 55.9%) or high-risk (OR:12.63 [9.89–16.13]; sensitivity 5.4%; specificity 99.1%) had higher odds of refractory VF/VT. Results was similar in the validation cohort (n = 765, AUROC = 0.672). ConclusionsPatients at higher risk for refractory VF/VT can be identified early in EMS care.

Procainamide for shockable rhythm cardiac arrest in the Resuscitation Outcome Consortium

BackgroundWith recent negative studies of amiodarone and lidocaine for cardiac arrest, research into other antiarrhythmics is warranted. Literature on procainamide in cardiac arrest is limited. We evaluated procainamide for out-of-hospital cardiac arrests (OHCA) from the Resuscitation Outcomes Consortium (ROC). MethodsWe included all ROC Epistry 3 OHCAs with an initial shockable rhythm that received an antiarrhythmic. We stratified cases by antiarrhythmic: procainamide, amiodarone, or lidocaine. The outcomes were prehospital return of spontaneous circulation (ROSC), ROSC in the ED, and survival to hospital discharge. We defined propensity scores based on possible confounders utilizing 1:1 propensity score matching to compare procainamide to amiodarone and lidocaine. We analyzed the matched data using logistic regression. We also used multivariable logistic regression to evaluate the association between antiarrhythmic and outcomes. Results3087 subjects met inclusion criteria; 51 patients received only procainamide, 1776 received amiodarone, and 1418 received lidocaine. On propensity score analysis and compared to procainamide, amiodarone had similar prehospital ROSC (OR 0.7, 95% CI 0.3–1.8), ED ROSC (OR 0.6, 95% CI 0.3–1.3), and survival (OR 1.0, 95% CI 0.3–3.1). Lidocaine also had a similar prehospital ROSC (OR 0.9, 95% CI 0.4–2.2), ED ROSC (OR 1.2, 95% CI 0.5–2.7), and survival (OR 1.4, 95% CI 0.5–4.0). However, using multivariable regression, amiodarone had lower prehospital ROSC than procainamide (aOR 0.3, 95% CI 0.1–0.6). ConclusionsWhile associated with increased prehospital ROSC when compared with amiodarone using multivariable regression, procainamide otherwise had similar prehospital ROSC, ED ROSC, and survival. The role of procainamide in OHCA remains unclear.

Out-of-hospital cardiac arrests terminated without full resuscitation attempts: Characteristics and regional variability

BackgroundOut-of-hospital cardiac arrest (OHCA) investigations may elect to exclude cases with resuscitation terminated for reasons other than a full resuscitative attempt. We sought to examine characteristics of these cases and regional variability in classification. MethodsUsing the North American Resuscitation Outcomes Consortium Epistry, we included adult emergency medical services (EMS)-treated cases, examining the rationale (“futility”, do-not resuscitate [DNR] order, “verbal directive“, or “obvious death”) and timing of resuscitation termination, and the timing of ROSC among hospital-discharge survivors. We tested regional variability in EMS patient arrival-to-termination intervals with one-way ANOVA. ResultsOf 63,554 included cases, 27,232 were declared dead in the prehospital setting: (1) 23,009 (36%) for futility (after a median of 24 minutes [IQR 19–31] of professional resuscitation); (2) 1622 (2.6%) for a DNR order (at 6.3 minutes [IQR 3.0–11]); (3) 1018 (1.6%) for a verbal directive (at 12 minutes [IQR 7.0–17]); and, (4) 1583 (2.5%) for obvious death (at 5.4 minutes [IQR 3.0–9.0]). The EMS patient arrival-to-ROSC interval among hospital-discharge survivors was 7.7 (3.8–13) minutes. Among regions, 0.20–12% and 0.20–5.3% were terminated to due to obvious death or verbal directives, respectively. There were significant regional differences in the EMS patient arrival-to-termination interval for futility (p < 0.010) and obvious death (p < 0.010). ConclusionThere is significant variation in the rationale and interval until termination of resuscitation between regions. Cases terminated due to obvious death or DNR orders/verbal directives are often treated with similar durations of resuscitation as survivors. These data highlight a considerable risk of bias in between-region comparisons or observational analyses.

Abstract 126: Intravenous Versus Intraosseous Epinephrine Administration for Pediatric Patients with Out-of-hospital Cardiac Arrest

Introduction: The 2015 American Heart Association Guidelines for Cardiopulmonary Resuscitation recommend intravenous (IV) or intraosseous (IO) epinephrine administration for pediatric patients with out-of-hospital cardiac arrest (OHCA). However, it is unknown whether the route of epinephrine administration affects patient outcomes. Our objective was to evaluate the association between the route of epinephrine administration and survival. Methods: We conducted a secondary analysis of the Resuscitation Outcomes Consortium Epistry, a prospective multicenter OHCA registry from 2011 through 2015 in North America. We included pediatric patients (≤18 years) with OHCA for whom emergency medical services (EMS) providers attempted resuscitation and administered epinephrine via IV or IO. We excluded patients who received endotracheal epinephrine, received both IV and IO epinephrine, received IV epinephrine with failed IO access, and received IO epinephrine with failed IV access. The primary outcome was survival to hospital discharge. We used multivariable logistic regression and adjusted for age, sex, initial rhythm, location of arrest, witness status, receiving layperson cardiopulmonary resuscitation, 9-1-1 call to EMS arrival, and advanced airway management. We also conducted a propensity score matching analysis with the same covariates. Results: Of the eligible 831 pediatric patients with OHCA, 226 (27.2%) received IV epinephrine and 605 (72.8%) IO epinephrine. Median interval between 9-1-1 call and epinephrine administration was 16.4 minutes (interquartile range [IQR] 12.9-21.0) in IV group and 16.2 minutes (IQR 12.8-20.0) in IO group. In the logistic regression model, the adjusted odds ratio (OR) of the IO group for survival to hospital discharge was 0.99 (95% confidence interval [CI] 0.41-2.40), compared with the IV group. Similarly, in the propensity score analysis, 218 patients underwent matching with good balance (standardized differences &lt;0.25 for all covariates) and the OR of the IO group for survival to hospital discharge was 1.00 (95% CI 0.38-2.62). Conclusions: We observed no significant difference in survival to hospital between pediatric patients with OHCA who received epinephrine via IV and IO routes.

Abstract 257: Adherence to the Termination Recommendations in the Universal Termination of Resuscitation Rule and Survival After Out-of-hospital Cardiac Arrest

Introduction: Survival after out-of-hospital cardiac arrest (OHCA) varies across emergency medical services (EMS) systems, but the EMS practices that contribute to the outcome variation are unclear. We evaluated the association between EMS agency variation in adherence to the termination recommendations in the Universal Termination of Resuscitation (TOR) rule and survival after OHCA. Methods: We conducted a secondary analysis of the Resuscitation Outcomes Consortium Epistry, a prospective multicenter OHCA registry in North America. We included adults (≥ 18 years) with OHCA for whom EMS providers attempted resuscitation from 2011 through 2015. The main exposure was proportion of patients meeting the Universal TOR rule (not EMS-witnessed arrest, no return of spontaneous circulation prior to transport, and no shock delivery prior to transport) among those who had prehospital TOR at the level of EMS agency. We categorized EMS agencies into quartiles based on the adherence to the Universal TOR rule. Our primary outcome was survival to hospital discharge. We used multilevel modified Poisson regression model, including patient-level and EMS-level covariates with patients nested within EMS agencies. Results: We included 43,656 EMS-treated OHCAs from 112 EMS agencies. The median adherence to the Universal TOR rule was 75.6% (interquartile range [IQR] 67.5-83.7) across EMS agencies. Compared with patients resuscitated at EMS agencies in the quartile of the lowest adherence (median adherence 62.5% [IQR 58.9-65.7]), survival to hospital discharge was inversely associated with treatment at EMS agencies in the second quartile (median adherence 72.6% [IQR 70.2-74.7]) (adjusted risk ratio [aRR] 0.83, 95% confidence interval [CI] 0.71-0.96), the third quartile (median adherence 80.6% [IQR 78.5-81.9]) (aRR 0.71, 95% CI 0.60-0.85), and the fourth quartile (median adherence 90.6% [IQR 86.2-93.7]) (aRR 0.68, 95% CI 0.58-0.80). Conclusions: In this large cohort study of adult patients with OHCA, we observed variation in the adherence to the Universal TOR rule’s termination recommendations across EMS agencies, and an association between higher EMS-level adherence and worse survival to hospital discharge after OHCA.

Abstract 258: Adherence to the Transport Recommendations in the Universal Termination of Resuscitation Rule and Survival After Out-of-Hospital Cardiac Arrest

Introduction: Survival after out-of-hospital cardiac arrest (OHCA) varies across emergency medical services (EMS) systems. The contribution of EMS practices variation on the outcome disparities is unclear. We evaluated the association between EMS agency variation in adherence to the transport recommendations in the Universal Termination of Resuscitation (TOR) Rule and survival after OHCA. Methods: We conducted a secondary analysis of the Resuscitation Outcomes Consortium Epistry. We included adults (≥ 18 years) with OHCA for whom EMS providers attempted resuscitation from 2011 through 2015. The main exposure was the proportion of patients for whom the Universal TOR Rule recommended transport (i.e., meeting any one of the following criteria, EMS-witnessed arrest; return of spontaneous circulation prior to transport; or shock delivery prior to transport) among those transported to hospitals, at the level of EMS agency. We then categorized EMS agencies into quartiles. Our primary outcome was survival to hospital discharge. We used multilevel modified Poisson regression model, including patient-level and EMS-level covariates with patients nested within EMS agencies. Results: We included 42,584 EMS-treated OHCAs from 112 EMS agencies. The median proportion of patients for whom the TOR rule recommended transport among those transported was 88.2% (interquartile range [IQR] 76.1-96.7) across EMS agencies. Compared with the patients treated at EMS agencies in the quartile of the lowest proportion (the median proportion 66.7%[ IQR 50.9-71.7]), survival to hospital discharge was associated with treatment at EMS agencies in the second quartile (the median proportion 83.0% [IQR 79.8-85.3]) (adjusted risk ratio [aRR] 1.12, 95% confidence interval [CI] 0.96-1.31), the third quartile (the median proportion 93.0% [IQR 89.7-95.6]) (aRR 1.58, 95% CI 1.32-1.87), and the fourth quartile (the median proportion 100% [IQR 98.5-100]) (aRR 1.86, 95% CI 1.59-2.19). Conclusions: In this large cohort study of adult patients with OHCA, treatment at EMS agencies with higher proportion of patients who met transport criteria of the Universal TOR rule among transported patients was associated with survival to hospital discharge.

The impact of increased chest compression fraction on survival for out-of-hospital cardiac arrest patients with a non-shockable initial rhythm

ObjectiveWe evaluated the effect of chest compression fraction (CCF) on survival to hospital discharge and return of spontaneous circulation (ROSC) in out-of-hospital cardiac arrest (OHCA) patients with non-shockable rhythms. MethodsThis is a retrospective analysis (completed in 2016) of a prospective cohort study which included OHCA patients from ten U.S. and Canadian sites (Resuscitation Outcomes Consortium Epistry and PRIMED study (2007–2011)). We included all OHCA victims of presumed cardiac aetiology, not witnessed by emergency medical services (EMS), without automated external defibrillator shock prior to EMS arrival, receiving > 1 min of CPR with CPR process measures available, and initial non-shockable rhythm. We measured CCF using the first 5 min of electronic CPR records. ResultsDemographics of 12,928 adult patients were: mean age 68; male 59.9%; public location 8.5%; bystander witnessed 35.2%; bystander CPR 39.3%; median interval from 911 to defibrillator turned on 10 min:04 s; initial rhythm asystole 64.8%, PEA 26.0%, other non-shockable 9.2%; compression rate 80−120/min (69.1%); median CCF 74%; ROSC 25.6%; survival to hospital discharge 2.4%. Adjusted odds ratio (OR); 95% confidence intervals (95%CI) of survival for each CCF category were: 0−40% (2.00; 1.16, 3.32); 41−60% (0.83; 0.54, 1.24); 61−80% (1.02; 0.77, 1.35); and 81−100% (reference group). Adjusted (OR; 95%CI) of ROSC for each CCF category were: 0−40% (1.02; 0.79, 1.30); 41−60% (0.83; 0.72, 0.95); 61−80% (0.85; 0.77, 0.94); and 81−100% (reference group). ConclusionsWe observed an incremental benefit from higher CCF on the incidence of ROSC, but not survival, among non-shockable OHCA patients with CCF higher than 40%.

Abstract 483: Out of Hospital Cardiac Arrest Outcomes After Transitioning to Pit Crew Model

Introduction: One of the leading causes of untimely death as per the Resuscitation Outcomes Consortium Epistry for cardiac arrest is out of hospital cardiac arrest (OHCA). Adoption of the choreographed approach of the pit crew model resuscitation improved outcomes after OHCA in some previous studies. Hypothesis: Compare outcomes post OHCA before and after adopting a pit crew model approach in one of the largest counties in Kansas. Methods: The data was collected before (2010 – 2012) and after the pit crew (2013-2016) approach from 2010 to 2016. The patient demographics and resuscitation variables were similar and comparable including the emergency and fire department personnel. The primary outcome was the proportion of patients having sustained return of spontaneous circulation (ROSC). Secondary outcomes were average number of pauses &gt;10 seconds, cerebral performance post return of spontaneous circulation, and average cardio-pulmonary resuscitation (CPR) cycles to ROSC. Results: The patients who had sustained ROSC post pit crew approach was 67.9% vs 32.1% (p=&lt; 0.001). Average number of CPR pause time &gt; 10 seconds post pit crew model was 1 vs 5 (p=0.01). Cerebral performance post return of spontaneous circulation using pit crew approach with good cerebral performance was 47% vs 56% (p=0.2), moderate cerebral disability was 17% vs 23% (p=0.19), severe cerebral disability was 8% vs 11% (p=0.44) and in coma/vegetative state was 8% vs 16% (p=0.001). Average CPR cycles to ROSC was 6.63. Conclusion: This focused model of high-quality CPR performance with individualized assigned tasks with minimal interruptions has shown increased numbers of sustained ROSC. The pit crew model approach also has showed decline in the rates of cerebral performance especially with moderate and severe cerebral performance including the patients in coma or vegetative state which is mainly through continuous cerebral perfusion pressures. More studies with better follow-up care in coordination with hospital outcomes will be key for the pit crew approach to be adopted.

Does location matter? A proposed methodology to evaluate neighbourhood effects on cardiac arrest survival and bystander CPR.

Traditional variables used to explain survival following out-of-hospital cardiac arrest (OHCA) account for only 72% of survival, suggesting that other unknown factors may influence outcomes. Research on other diseases suggests that neighbourhood factors may partly determine health outcomes. Yet, this approach has rarely been used for OHCA. This work outlines a methodology to investigate multiple neighbourhood factors as determinants of OHCA outcomes. A retrospective, observational cohort study design will be used. All adult non-emergency medical service witnessed OHCAs of cardiac etiology within the city of Toronto between 2006 and 2010 will be included. Event details will be extracted from the Toronto site of the Resuscitation Outcomes Consortium Epistry-Cardiac Arrest, an existing population-based dataset of consecutive OHCA patients. Geographic information systems technology will be used to assign patients to census tracts. Neighbourhood variables to be explored include the Ontario Marginalization Index (deprivation, dependency, ethnicity, and instability), crime rate, and density of family physicians. Hierarchical logistic regression analysis will be used to explore the association between neighbourhood characteristics and 1) survival-to-hospital discharge, 2) return-of-spontaneous circulation at hospital arrival, and 3) provision of bystander cardiopulmonary resuscitation (CPR). Receiver operating characteristics curves will evaluate each model's ability to discriminate between those with and without each outcome. Discussion This study will determine the role of neighbourhood characteristics in OHCA and their association with clinical outcomes. The results can be used as the basis to focus on specific neighbourhoods for facilitating educational interventions, CPR awareness programs, and higher utilization of automatic defibrillation devices.

Abstract 18984: Discrepancy Between Originally Assigned and Adjudicated Causes of Out-of-Hospital-Cardiac-Arrest of “No Obvious Cause” in Young Patients

Background: Death due to out-of-hospital cardiac arrest (OHCA) is most commonly attributed to “no obvious cause” after review of the prehospital and in-hospital documentation. To establish cause of death in younger patients, autopsy and toxicology data are important, especially in younger patients. We examined the probable cause of death in a large urban cohort of younger OHCA patients. Methods: A prospective population-based registry of all OHCAs attended by Emergency Medical Services (EMS) in the Toronto area was used to identify cases from 2009-2012. Identified OHCAs were cases aged 2-45 who died and assigned ‘no obvious cause’ based on abstracted data from ambulance call reports and in-hospital chart review, including narrative review and contributing factors compliant with the Resuscitation Outcomes Consortium Epistry Manual of Operations. Cases with inadequate information (coroners and/or EMS), or with expected death (e.g. DNR or long term care) or homicide were then excluded. The remaining cases were adjudicated by 3 reviewers using additional data from coroner investigative statements, autopsy, toxicology and police reports, and classified as primary cardiac or another non-cardiac etiology. Results: A total of 2048 OHCA cases with no obvious cause were identified; of these, 547 were excluded. Of the remaining 1501 cases with complete information, 48.2% were treated by EMS. Of the treated cases, 41.3 % (299/724) of those assigned to ‘no obvious cause’ had an adjudicated cardiac etiology. Of the untreated group, 21.2% (165/777) had an adjudicated cardiac etiology. The majority consisted of drug overdoses (214/425; 50.3%) and other non-cardiac causes (49.7%) including trauma (Figure 1). Conclusions: In younger OHCA patients who die, the category "OHCA of no obvious cause”, on detailed review, is most often due to a non-cardiac cause. This observation may contribute to a better understanding of the etiology of sudden cardiac death in younger patients.

Determining Risk for Out-of-Hospital Cardiac Arrest by Location Type in a Canadian Urban Setting to Guide Future Public Access Defibrillator Placement

Automated external defibrillator use by lay bystanders during out-of-hospital cardiac arrest rarely occurs but can improve survival. We seek to estimate risk for out-of-hospital cardiac arrest by location type and evaluate current automated external defibrillator deployment in a Canadian urban setting to guide future automated external defibrillator deployment. This was a retrospective analysis of a population-based out-of-hospital cardiac arrest database. We included consecutive public location, nontraumatic, out-of-hospital cardiac arrests occurring in Toronto from January 1, 2006, to June 30, 2010, captured in the Resuscitation Outcomes Consortium Epistry database. Two investigators independently categorized each out-of-hospital cardiac arrest and automated external defibrillator location into one of 38 categories. Total site counts in each location category were used to estimate average annual per-site cardiac arrest incidence and determine the relative automated external defibrillator coverage for each location type. There were 608 eligible out-of-hospital cardiac arrest cases. The top 5 location categories by average annual out-of-hospital cardiac arrests per site were race track/casino (0.67; 95% confidence interval [CI] 0 to 1.63), jail (0.62; 95% CI 0.3 to 1.06), hotel/motel (0.15; 95% CI 0.12 to 0.18), hostel/shelter (0.14; 95% CI 0.067 to 0.19), and convention center (0.11; 95% CI 0 to 0.43). Although schools were relatively lower risk for cardiac arrest, they represented 72.5% of automated external defibrillator-covered locations in the study region. Some higher-risk location types such as hotel/motel, hostel/shelter, and rail station were severely underrepresented with respect to automated external defibrillator coverage. We have identified types of locations with higher per-site risk for cardiac arrest relative to others. We have also identified potential mismatches between cardiac arrest risk by location type and registered automated external defibrillator distribution in a Canadian urban setting.

Abstract 182: Risk of Cardiac Arrest by Location Type to Guide Future AED Placement in a Large Urban Center

Introduction: Public access defibrillation (PAD) programs can improve survival from out-of-hospital cardiac arrest (OHCA). We aimed to identify high risk public locations which should be prioritized for automated external defibrillator (AED) placement. Objectives: 1) To determine the average annual incidence of cardiac arrest by location type within the study area, 2) To describe current registered PAD deployment by location type. Methods: An observational cohort study using the Resuscitation Outcomes Consortium Epistry database. We included all public location, non-traumatic, EMS-treated OHCAs from January 1, 2006 to June 30, 2010 in the City of Toronto. The total site counts in each location category were derived from a city planning database and used as the denominator in calculating average annual per site cardiac arrest incidence. AED locations were obtained from an EMS registry. Two investigators independently categorized each OHCA and AED location. Disagreements were resolved by consensus. Results: There were 1297 OHCAs, of which 571 occurred on streets and could not be associated with a specific location type, leaving 726 eligible cases. The average age was 58±17.5 years, 82.7% were male and 13.9% survived to hospital discharge. Of all included patients, 44.9% had bystander CPR attempted and 9.5% had a bystander apply a defibrillator. Table 1 contains data from the top 15 location types ranked on average annual OHCAs per individual site. There were 1616 AED covered locations in the City of Toronto. 57.3% of the registered AED sites were elementary and secondary schools, 16.0% were post secondary schools, 7.8% were offices and 4% were community or recreation centres. Conclusions: We have identified location types with highest risk for cardiac arrest. Most registered AEDs have been placed at Elementary and Secondary Schools which are relatively low risk for OHCA. Our data can guide future AED deployment to increase availability for use in public location OHCA.

The impact of increased chest compression fraction on return of spontaneous circulation for out-of-hospital cardiac arrest patients not in ventricular fibrillation

Objective Greater chest compression fraction (CCF, or proportion of CPR time spent providing compressions) is associated with better survival for out-of-hospital cardiac arrest (OOHCA) patients in ventricular fibrillation (VF). We evaluated the effect of CCF on return of spontaneous circulation (ROSC) in OOHCA patients with non-VF ECG rhythms in the Resuscitation Outcomes Consortium Epistry. Methods This prospective cohort study included OOHCA patients if: not witnessed by EMS, no automated external defibrillator (AED) shock prior to EMS arrival, received >1 min of CPR with CPR process measures available, and initial non-VF rhythm. We reviewed the first 5 min of electronic CPR records following defibrillator application, measuring the proportion of compressions/min during the resuscitation. Results Demographics of 2103 adult patients from 10 U.S. and Canadian centers were: mean age 67.8; male 61.2%; public location 10.6%; bystander witnessed 32.9%; bystander CPR 35.4%; median interval from 911 to defibrillator turned on 8 min:27 s; initial rhythm asystole 64.0%, PEA 28.0%, other non-shockable 8.0%; median compression rate 110/min; median CCF 71%; ROSC 24.2%; survival to hospital discharge 2.0%. The estimated linear effect on adjusted odds ratio with 95% confidence interval (OR; 95%CI) of ROSC for each 10% increase in CCF was (1.05; 0.99, 1.12). Adjusted (OR; 95%CI) of ROSC for each CCF category were: 0–40% (reference group); 41–60% (1.14; 0.72, 1.81); 61–80% (1.42; 0.92, 2.20); and 81–100% (1.48; 0.94, 2.32). Conclusions This is the first study to demonstrate that increased CCF among non-VF OOHCA patients is associated with a trend toward increased likelihood of ROSC.

Perishock Pause

Background— Perishock pauses are pauses in chest compressions before and after defibrillatory shock. We examined the relationship between perishock pauses and survival to hospital discharge. Methods and Results— We included out-of-hospital cardiac arrest patients in the Resuscitation Outcomes Consortium Epistry–Cardiac Arrest who suffered arrest between December 2005 and June 2007, presented with a shockable rhythm (ventricular fibrillation or pulseless ventricular tachycardia), and had cardiopulmonary resuscitation process data for at least 1 shock (n=815). We used multivariable logistic regression to determine the association between survival and perishock pauses. In an analysis adjusted for Utstein predictors of survival, the odds of survival were significantly lower for patients with preshock pause ≥20 seconds (odds ratio, 0.47; 95% confidence interval, 0.27 to 0.82) and perishock pause ≥40 seconds (odds ratio, 0.54; 95% confidence interval, 0.31 to 0.97) compared with patients with preshock pause &lt;10 seconds and perishock pause &lt;20 seconds. Postshock pause was not independently associated with a significant change in the odds of survival. Log-linear modeling depicted a decrease in survival to hospital discharge of 18% and 14% for every 5-second increase in both preshock and perishock pause interval (up to 40 and 50 seconds, respectively), with no significant association noted with changes in the postshock pause interval. Conclusions— In patients with cardiac arrest presenting in a shockable rhythm, longer perishock and preshock pauses were independently associated with a decrease in survival to hospital discharge. The impact of preshock pause on survival suggests that refinement of automatic defibrillator software and paramedic education to minimize preshock pause delays may have a significant impact on survival.

The Relationship Between Out-of-Hospital Airway Management and Outcome Among Trauma Patients with Glasgow Coma Scale Scores of 8 or Less

Background. Airway management remains a fundamental component of optimal care of the severely injured patient, with endotracheal intubation representing the definitive strategy for airway control. However, multiple studies document an association between out-of-hospital intubation and increased mortality for severe traumatic brain injury. Objectives. To explore the relationship between out-of-hospital intubation attempts and outcome among trauma patients with Glasgow Coma Scale (GCS) scores ≤8 across sites participating in the Resuscitation Outcomes Consortium (ROC). Methods. The ROC Epistry–Trauma, an epidemiologic database of prehospital encounters with critically injured trauma victims, was used to identify emergency medical services (EMS)-treated patients with GCS scores ≤8. Multiple logistic regression was used to explore the association between intubation attempts and vital status at discharge, adjusting for the following covariates: age, gender, GCS score, hypotension, mechanism of injury, and ROC site. Sites were then stratified by frequency of intubation attempts and chi-square test for trend was used to associate the frequency of intubation attempts with outcome. Results. A total of 1,555 patients were included in this analysis; intubation was attempted in 758 of these. Patients in whom intubation was attempted had higher mortality (adjusted odds ratio [OR] 2.91, 95% confidence interval [CI] 2.13–3.98, p < 0.01). However, sites with higher rates of attempted intubation had lower mortality across all trauma victims with GCS scores ≤8 (OR 1.40, 95% CI 1.15–1.72, p < 0.01). Conclusions. Patients in whom intubation is attempted have higher adjusted mortality. However, sites with a higher rate of attempted intubation have lower adjusted mortality across the entire cohort of trauma patients with GCS scores ≤8. Key words: prehospital intubation; traumatic brain injury; airway management; paramedic; outcomes; major trauma victim; ventilation; mortality; Glasgow Coma Scale score

Variation in out-of-hospital cardiac arrest resuscitation and transport practices in the Resuscitation Outcomes Consortium: ROC Epistry–Cardiac Arrest

ObjectivesTo identify variation in patient, event, and scene characteristics of out-of-hospital cardiac arrest (OOHCA) patients assessed by emergency medical services (EMS), and to investigate variation in transport practices in relation to documented prehospital return of spontaneous circulation (ROSC) within eight regional clinical centers participating in the Resuscitation Outcomes Consortium (ROC) Epistry–Cardiac Arrest. MethodsOOHCA patient, event, and scene characteristics were compared to identify variation in treatment and transport practices across sites. Findings were adjusted for site and standard Utstein covariates. Using logistic regression, these covariates were modeled to identify factors related to the initiation of transport without documented prehospital ROSC as well as survival in these patients. Setting: Eight US and Canadian sites participating in the ROC Epistry–Cardiac Arrest. Population: Persons ≥20 years with OOHCA who (a) received compressions or shock by EMS providers and/or received bystander AED shock or (b) were pulseless but received no EMS compressions or shock between December 2005 and May 2007. Results23,233 OOHCA cases were assessed by EMS in the defined period. Resuscitation (treatment) was initiated by EMS in 13,518 cases (58%, site range: 36–69%, p<0.0001). Of treated cases, 59% were transported (site range: 49–88%, p<0.0001). Transport was initiated in the absence of documented ROSC for 58% of transported cases (site range: 14–95%, p<0.0001). Of these transported cases, 8% achieved ROSC before hospital arrival (site range: 5–21%, p<0.0001) and 4% survived to hospital discharge (site range: 1–21%, p<0.0001). In cases with transport from the scene initiated after documented ROSC, 28% survived to hospital discharge (site range: 18–44%, p<0.0001). ConclusionInitiation of resuscitation and transport of OOHCA and the reporting of ROSC prior to transport markedly varies among ROC sites. This variation may help clarify reported differences in survival rates among sites and provide a target for identifying EMS practices most likely to enhance survival from OOHCA.

Incidence of Rearrest After Return of Spontaneous Circulation in Out-of-Hospital Cardiac Arrest

Background. Return of spontaneous circulation (ROSC) occurs in 35.0 to 61.0% of emergency medical services (EMS)-treated out-of-hospital cardiac arrests (OHCAs); however, not all patients achieving ROSC survive to hospital arrival or discharge. Previous studies have estimated the incidence of some types of rearrest(RA) at 61.0 to 79.0%, and the electrocardiogram (ECG) waveform characteristics of prehospital RA rhythms have not been previously described. Objectives. We sought to determine the incidence of RA in OHCA, to classify RA events by type, and to measure the time from ROSC to RA. We also conducted a preliminary analysis of the relationship between first EMS-detected rhythms and RA, as well as the effect of RA on survival. Methods. The Pittsburgh Regional Clinical Center of the National Heart, Lung, and Blood Institute (NHLBI) -sponsored Resuscitation Outcomes Consortium (ROC) provided cases from a population-based cardiac arrest surveillance program, ROC Epistry. Only OHCA cases of nontraumatic etiology with available and adequate ECG files were included. We analyzed defibrillator–monitor ECG tracings (Philips MRX), patient care reports (PCRs), and defibrillator audio recordings from EMS-treated cases of OHCA spanning the period from October 2006 to December 2008. We identified ROSC and RA through interpretation of ECG tracings and audio recordings. Rearrest events were categorized as ventricular fibrillation (VF), pulseless ventricular tachycardia (VT), asystole, and pulseless electrical activity (PEA) based on ECG waveform characteristics. Proportions of RA rhythms were stratified by first EMS rhythm and compared using Pearson's chi-square test. Logistic regression was used to test the predictive relationship between RA and survival to hospital discharge. Results. Return of spontaneous circulation occurred in 329 of 1,199 patients (27.4% [95.0% confidence interval (CI): 25.0–30.0%]) treated for cardiac arrest. Of these, 113 had ECG tracings that were available and adequate for analysis. Rearrest occurred in 41 patients (36.0% [95.0% CI: 26.0–46.0%]), with a total of 69 RA events. Survival to hospital discharge in RA cases was 23.1% (95.0% CI: 11.1–39.3%), compared with 27.8% (95.0% CI: 17.9–39.6%) in cases without RA. Counts of RA events by type were as follows: 17 VF (24.6% [95% CI: 15.2–36.5%]), 20 pulseless VT (29.0% [95.0% CI: 18.7–41.2%]), 26 PEA (37.0% [95.0% CI: 26.3–50.2%]), and six asystole (8.8% [95.0% CI: 3.3–18.0%]). Rearrest was not predictive of survival to hospital discharge; however, initial EMS rhythm was predictive of RA shockability. The overall median (interquartile range) time from ROSC to RA among all events was 3.1 (1.6–6.3) minutes. Conclusion. In this sample, the incidence of RA was 38.0%. The most common type of RA was PEA. Shockability of first EMS rhythm was found to predict subsequent RA rhythm shockability.

Public Access Defibrillation

Sudden cardiac arrest (SCA) is recognized as a serious public health problem, accounting for 250 000 to 300 000 deaths per year; it is now the third-leading cause of death behind cancer and nonsudden cardiovascular deaths.1,2 Immediate, well-performed cardiopulmonary resuscitation (CPR) and early defibrillation are the only out-of-hospital interventions that improve outcomes.3 The chain of survival relies on lay responders and emergency medical services (EMS) to initiate the potentially life-saving procedures of CPR and defibrillation. Articles see pp 510 and 518 In 1994, the American Heart Association (AHA) convened the first conference on public access defibrillation (PAD) to introduce the strategy of placing easy-to-use defibrillators in public places to decrease the death rate from SCA.4 Specific recommendations encouraged the stakeholders (the AHA, the US Food and Drug Administration, the National Institutes of Health, industry, and communities) to facilitate PAD by developing user-friendly, less-expensive automated external defibrillators (AEDs); testing the concept within large clinical trials; and organizing communities to promote and support effective PAD programs. Widespread CPR and AED training of the public was emphasized. In the ensuing 15 years, many of these recommendations have been heeded, and PAD programs are now commonplace. The National Institutes of Health–sponsored PAD trial demonstrated that survival doubled when events occurred in communities equipped and trained with CPR and AEDs compared with CPR alone.5 Within the Resuscitations Outcomes Consortium (ROC), out-of-hospital cardiac arrest victims had a markedly increased chance of survival if the first shock was delivered by a bystander using an AED rather than by EMS.6 PAD programs in airports, airlines, and casinos have also validated the effectiveness of the concept. Out-of hospital cardiac arrest is treatable, and outcomes can be improved with currently available approaches. Multiple locations have been recognized as having a higher incidence of cardiac arrest …

Abstract P192: What is the Role of Chest Compression Depth during Out-of-Hospital CPR?

Introduction: Current CPR compression depth guidelines were empirically derived. We sought to study patterns of CPR compression depth and their associations with patient outcomes in out-of-hospital cardiac arrest (OOHCA). Methods: We studied OOHCA patients from the Resuscitation Outcomes Consortium Epistry - Cardiac Arrest for whom electronic CPR data were available from proprietary accelerometer technology attached to the prehospital defibrillators. We calculated anterior chest wall depression in millimeters and the period of active CPR (chest compression fraction [CCF]) for each minute of CPR. We controlled for covariates including compression rate and calculated adjusted odds ratios (OR) for any return of circulation (ROSC) and 24 hour survival. We calculated unadjusted OR for hospital discharge. Results: We included 615 adult patients from 6 U.S. and Canadian cities with these characteristics: mean age 68.9; male 62 %; witnessed 43%; bystander CPR 31%; initial rhythms - VF/VT 25%, PEA 17%, asystole 43%, unspecified non-shockable 15%; mean compression rate 103/min; mean compression depth &lt;38mm 51%, 38–51mm 39%, &gt;51mm 11%; median CCF 0.66; outcomes - ROSC 57%, 24 hour survival 18%, discharge 5%. We found an inverse association between depth and compression rate (P&lt;0.0001; see Table ), no association between depth and CCF (P=0.30), and a positive association between CCF and rate (P&lt;0.0001). ORs with 95% CIs for each 5mm increment in compression depth and the outcomes were: 1) ROSC - adjusted OR 1.06 (0.97–1.16), 2) 24 hour survival - adjusted OR 1.01 (0.98–1.03), 3) discharge - unadjusted OR 1.13 (0.95–1.34). Conclusions: We found half of patients received suboptimal compression depth, an inverse association between compression depth and rate, and no clear association between survival and increased compression depth. Further study is required to determine the optimum chest compression depth and its interaction with rate and CCF in order to maximize outcomes. Compression Rate versus Compression Depth

Rationale, development and implementation of the Resuscitation Outcomes Consortium Epistry—Cardiac Arrest

To describe the development, design and consequent scientific implications of the Resuscitation Outcomes Consortium (ROC) population-based registry; ROC Epistry-Cardiac Arrest. The ROC Epistry--Cardiac Arrest is designed as a prospective population-based registry of all Emergency Medical Services (EMSs)-attended 9-1-1 calls for patients with out-of-hospital cardiac arrest occurring in the geographical area described by the eight US and three Canadian regions. The dataset was derived by an North American interdisciplinary steering committee. Enrolled cases include individuals of all ages who experience cardiac arrest outside the hospital, with evaluation by organized EMS personnel and: (a) attempts at external defibrillation (by lay responders or emergency personnel), or chest compressions by organized EMS personnel; (b) were pulseless but did not receive attempts to defibrillate or CPR by EMS personnel. Selected data items are categorized as mandatory or optional and undergo revisions approximately every 12 months. Where possible all definitions are referenced to existing literature. Where a common definition did not exist one was developed. Optional items include standardized CPR process data elements. It is anticipated the ROC Epistry--Cardiac Arrest will enroll between approximately 9000 and 13,500 treated all rhythm arrests and 4000 and 5000 ventricular fibrillation arrests annually and approximately 8000 EMS-attended but untreated arrests. We describe the rationale, development, design and future implications of the ROC Epistry--Cardiac Arrest. This paper will serve as the reference for subsequent ROC manuscripts and for the common data elements captured in both ROC Epistry--Cardiac Arrest and the ROC trials.